Polyvinyl chloride stabilized with mixtures of a pcl3-bis phenol reaction product, epoxy resin and heavy metal salt



United States Patent 3,400,088 1 POLYVINYL CHLORIDE'STABILIZED WITH MIX- TURES OF A PCl -BIS PHENOL REACTION PROD- .UCT, EPOXY RESIN AND HEAVY METAL SALT Yolande Bourgau, Neuville, and Jacques Fritz, Lyon, France, assignors to Societe Progil, Paris, France No Drawing. Filed Feb. 9, 1965, Ser. No. 431,456 Claims priority, application6 France, Feb.'10, 1964, 963 1 4 7 Claims. 61. 260-23) ABSTRACT OF THE DISCLGSURE Stabiliier additive for polyvinyl chloride resin, comprising the substance obtained by reactingone mole of phosphorus trichloride with two to four moles of 4,4-dihydroxydiphenyl-dimethyl-methane, an epoxy resin and 5 The present invention relates to a new stabiliser for plastic compositions, serving particularly for stabilising polyvinyl resins against heat and/or light. It also has for its object the resinous compositions, particularly polyvinyl chlorides, stabilised in this way.

It is known that the addition of certain organic phosphites to polyvinyl resins exerts, by chelation, a stabilising action on these resins, when they are used in conjunction with epoxy resins and salts of fatty acids of heavy metals, as for example the laurates, stearates and ricinoleates of cadmium, barium or lead.

Among thephosphites described for this purpose, there may be particularly mentioned the trialkyl phosphites, namely, trimethyl and tridecyl phosphites; acid phosphites of dialkyls, such as dioctyl or dilauryl; triaryl phosphites, particularly phenyl or cresyl phosphites; monoalkyl or dialkyl and diphenyl or mono henyl phosphites, as well as hydroxyaryl phosphites.

One of the best stabilisers among the already known class of organic phosphites is tri-(p-tert.butylphenyl) phosphite.

According to the present invention, the stabilising power of the epoxy resins and of the heavy metal salts is distinctly improved when these additives have incorporated therein, instead of the conventional hydrocarbon phosphites, phosphorus-containing hydroxyaryl compounds obtained by theaction of one mol of phosphorus trihalide (particularly PO1 on at least two mols of a diphenol of the formula:

in which R and R may be like or different and represent a hydrogen atom or a lower alkyl radical.

These compounds are characterised in that they contain phosphorus bonded to the aromatic rings by means of oxygen bridges, and that these rings carry free phenolic OH groups.

Stabilisers according to the invention which are particularly suitable for the stabilisation of vinyl resins are the phosphorus derivatives of Bisphenol A, that is to say, of the diphenol (1) in which R and R are CH radicals; these derivatives are formed by the action of PCl under heat of at least 2 mols of dihydroxy-4,4'-diphenyldimethylmethane, followed by the removal of the HCl thus produced.

The preparation of such hydroxyaryl compounds containing phosphorus can be carried out by starting with up to 4 mols and preferably 2 to 4 mols of a diphenol. It

3,400,088 Patented Sept. 3, 1968 may be effected by heating the reagents in an inert solvent or in the presence of an organic base.

However, according to the present invention, it is particularly advantageous to prepare the new stabilisers by the progressive introduction of phosphorus trichloride into molten Bisphenol A, kept at a temperature of to 160 C., and subsequently eliminating the HCl which has formed, by heating under atmospheric or reduced pressure.

One first practical method of operation consists in heating the Bishpenol A to a temperature higher than its melting point, for example to between 150 and 160 C., then progressively introducing the phosphorus trichloride into the molten product which has been cooled to 80 to C. The reaction is completed by heating to the region of to C. under atmospheric pressure, or even to 70 to 80 C. under a pressure of 30 to 50 mm. Hg, until the HCl formed is completely eliminated, The compounds thus obtained are solids of resinous appearance and yellowish in colour, in which the percentage of phosphorus varies between wide limits, for example, between 3 and 8%.

The reaction with P01 can be completed more quickly, namely in about 20 to 30 minutes, if the introduction of phosphorus trichloride is commenced while the bishpenol is in the region of C.; while introducing the reagent, the temperature is allowed to fall so that it is in the region of 90 to 110 C. after completing the introduction thereof. The operation is then completed by heating for 1 to 3 hours to the region of 140 to 150 C. for eliminating the hydrochloric acid which has formed. These operations, conducted at higher temperatures than in the first embodiment referred to above, yield an excellent stabiliser. Furthermore, this procedure avoids any possible drawbacks due to the supercooling of bisphen01; it also allows one to use more than 3 moles of bisphenol per mole of PCl without difiiculties which otherwise could arise because of the strong viscosity of the medium.

According to a preferred characteristic of the invention the reaction between phosphorus trihalide and hydroxyaryl is carried out in carbon dioxide atmosphere; less coloured products are thus obtained.

It can be assumed that the resinous solids which constitute the phosphorus-containing hydroxyaryl compounds obtained according to the invention, as described above, comprise hydroxyaryl phosphites; however, the constitution thereof is still not well established and it appears to be fairly complex. In any case, these compounds differ from known phosphites, especially from those which are obtained by transesterification of a dialkyl, trialkyl or aryl phosphite with a phenol or a polyphenol. Thus, clear differences appear between the chromatographic strips recorded on the hand with the compounds obtained by the action of phosphorus trichloride on Bisphenol A, as indicated above, and on the other hand the tri[bis-(p-hydroxyphenyl)] propane phosphilte prepared by the conventional method of transesterification, namely, by heating Bisphenol A with triphenyil phosphite.

Furthermore, the behaviour in the stabilisation of plastic compositions of phosphorous compounds according to the invention is very different form that of the corresponding phosphites prepared by transesterification; the said compounds are found to be better stabilisers than the phosphites obtained by transesterification from the same phenols.

The incorporation of the phosphorous compounds according to the invention into vinyl polymers, particularly polyvinyl chloride, takes place by known methods, for example by suitably plasticised resin in powder form being mixed on an external mixer with an epoxy resin, one or more organic salts of heavy metals, and a cer- 4 tain proportion of said phosphorous compounds accord- For carrying out the heat stability test in respect of mg to the invention. each composition, the specimens were placed in an oven The Propertlens of these compounds added to the Poly at 177 C., and then the colouring therof was examined vinyl chloride resin may vary within wide limits; nevertheless, quantities of 0.1 to 1% of the weight of resin or 2 to 20% of the total weight of the costabilisers,

as a function of time. The results obtained are set out 5 in the following table, where the comparison specimen preferably 2 to are particularly suitable. The total has the composition eerresponeing to the fefmula of the three stabilisers is preferably between 1 and 5% cated above, but does not contalh y phosphlto P of the weight of the resin to be stabilised. phorous compound.

Colourings Time (iiiin.) Comparison A B C D E F G 30 Colourless.. Colourless Colourless Colourless Colourless Colourless Colourless Colourless. 60 Pale yellow do do do .do do ..do D0. 80 Light orange do.. Do. 100 Deep orange do. Do. 120.. Very 1t. Light yellow.

. 0 do do do Do. Liglat yellow Ligliit yell0w Fast yellow... Light yellow Do. o o

Orange-brown.-. Deep yellow Orange yellow. Black- Orange-brown... Orange brown.

Black B lack.

The following examples are given in nonlimiting man- The results obtained clearly show the excellent bener and show how the invention may be carried into effect. haviour under heat of the compositions A to D containing They illustrate the beneficial effect of the phosphorous phosphorus compounds according to the invcntion.Wherecompounds derived from Bisphenol A on the heat stabilias the specimens containing triphenylphosphite, normally sation and light stabilisation of plasticised polyvinyl chlorused commercially, are already black after 210 minutes ide, and show clearly the superiority of these stabilisers at 177 C., and those which contain p-tert.butylphenol over the phosphites normally used commercially. phosphite (one of the best known stabilisers) assume the Exam 1 same shade after 240 minutes, the compositions accordmg to the invention still remain capable of use for several Compounds Containing Phosphorous are P p from tens of minutes and only become black after 310 minutes. dihydroxy-4,4'-diphenyldimethylmethane (Bisphenol A) by progressive addition of 1 mol of PC1 at a tempera- Example 2 mm from to to quantities of molten A series of stability tests with respect to ultraviolet Phenol A Whloh y between 2 and 111015, and then rays of the compositions A to D according to the invenhoatihg in Vaouo (about 40 at to 0 tion, the compositions E, F and G containing known Solids of reshlous appearance and yellowish in Colour organic phosphites and also of the comparison mixture are obtained, and the Phosphorous Contents y Weight free from phosphorus was carried out: the apparatus thereof y from to 40 used was that which French Rubber Institute has devel- A series of Compositions is then P p y intro oped and standardised for such measurements. ducihg each of thoso p using an external mixer, Specimens with the dimensions 70 x 30 mm., cut from into a polyvinyl chloride plasticised with dioctyl Phthalate, sheets with a thickness of 1.8 111111., obtained as indicated in which conventional costabilisers are likewise incorpi Example 1, are arranged at 15 cm, f m a Series of orated. By way of comparison, similar compositions have 3 high-pressure ultra-violet lamps with a power per unit been prepared, in which the compounds according to the of 125 watts. The temperature of the specimens is kept invention were replaced by phosphites known as Sta below 60 C. by a fan. After exposure for 5 to 8 hours e A yp formula 18 out In the followms tableunder the conditions indicated above, it was found that Ingredients; Parts by weight the test specimemof the comparison composition had Polyvinyl Chloride in powder f 100 assumed a yellowish orange colour and that the test Dioctyl phthalate 50 p cimens of formulae E, F and G had become yellowish.

Epoxy resin (Epikote 3 4 1 The specimens corresponding to the compositions A to and Cd laurate (Ba/Cd=2) 1 5 D, on the other hand, had remained practically colourless. Phosphorous compound, or phosphite 0.278 Exam P16 3 The i compounds used were: 685 g. of Bisphenol A (3 mols) are melted and brought f ez i Fq g f fg from to 155 C.; 138 g. of phosphorus trichloride (1 mol) are 3 .iP E contammg 0 i d from progressively added thereto in 25 minutes while stirring omp 0S1 05p orous q n prepare and while allowing the reaction mixture to cool slowly.

c P013 529 g contammg 1 of d from On completing the introduction of the PO1 this liquid omp 0S1 Ion OSP omus pi prep re mixture is at 102 C.; it is then heated to 145 C. and Pc13.a.nd Blsphenol contammg 549% of kept at this temperature for 1% hours, until all release Composmon D Phosphorous 'q i prepared from of hydrochloric acid has ceased. After cooling to normal PC13 l Blsphenpl contamlrig 5'66% of temperature, the solid, resinous and yellowish composiggfilgggigg: g' g ,ig x i fi ggig g p tion obtained had a content of 4.6% by weight of phosphorus.

Composition ii g pmpan; This composition, tested as stabilisation adjuvant for q g. i i g gz g g f fig g polyvinyl chloride, in the manner described 1n Example gis g ig gig aPatent No 1 2 p P 1, gives the same results as composition B.

The sheets removed from the external mixer and Example 4 obtained from each composition were pressed for 1 min- The preparation according to the first paragraph of ute at 175 C. in order to obtain sheets with a thickness Example 1 is repeated, while during the reaction a carbon of 1.8 mm., from which specimens of the dimensions dioxide atmosphere is maintained above the reaction 3 x 7 cm. were cut. medium within the vessel within which the operation is carried out. The resinous solids thus obtained are less coloured than the ones which were prepared in Example 1.

Example 5 In a preparation identical with that of Example 3, an atmosphere of CO has been continuously maintained above the reaction medium. The product which resulted from this operation was clearer than that of Example 3.

We claim:

1. Stabiliser additive for polyvinyl chloride resin which is a mixture of an epoxy resin, a heavy metal salt of an organic acid and at least 2% of the weight of said additive of an hydroxy-aryl compound containing combined phosphorus, which is obtained by reacting 1 mole of phosphorus trichloride with 2 to 4 moles of 4,4-dihydroxy-diphenyl-dimethyl-methane at 80 to 160 C.the final temperature being 80 to 110 C., and then heating from 110 C. to 50 C. until the hydrochloric acid formed is eliminated, the obtained product containing 3 to 8% by weight of combined phosphorus, and free phenolic OH groups, and being substantially free of chlorine atoms.

2. Stabilizer additive according to claim 1 in which the reaction between phosphorus trichloride and 4,4-dihydroxy-diphenyl-dimethyl-methane is carried out at a tempeature of 80 to 120 C. during 20 to 40 minutes.

3. Stabilizer additive according to claim 1, which contains by weight 10 to 60% of an epoxy resin, 20 to 90% of an organic salt of heavy metal and 2 to 20% of said phosphorus derivative.

4. Stabilizer additive in accordance with claim 3 wherein said organic salt of heavy metal comprises cadmium laurate and barium laurate.

5. A stabilizer additive for polyvinyl chloride comprising the reaction product of 1 mole of PCI with 2-4 moles of R1 R2 wherein R and R are hydrogen or lower alkyls, said reaction being carried out at an initial temperature of 160 C. and a final temperature of 80-1 10 C., said reaction being followed by heating to 150 C. until the formed HCl has been eliminated, said reaction product containing free phenolic OH groups and 3-8% by weight of combined phosphorus and being substantially free of chlorine atoms.

6. A stabilizer in accordance with claim 5 wherein R and R are hydrogen.

7. A composition of matter comprising polyvinyl chloride resin and 1 to 5% by weight of the resin of the stabilizer additive of claim 1.

References Cited UNITED STATES PATENTS 2,625,521 1/1953 Fischer et al 260-23 2,997,454 8/1961 Leistner et a1 26045.8 3,112,286 11/1963 Morris et a1. 26029.7 3,192,243 6/1965 Gagliani 260-976 3,225,001 12/1965 Darsa 260-45.75

DONALD E. CZAJ A, Primary Examiner. R. A. WHITE, Assistant Examiner. 

